1. Field of the Invention
The present invention relates to flip top closures and in particular to flip top closures having child-resistant opening mechanisms. More particularly, the present invention relates to a flip top closure having a child-resistant mechanism in which the top is automatically aligned in a nonopening position when closed.
2. Discussion of the Prior Art
Child-resistant closures that require proper alignment for opening are well known in the art. Such closures often have components, such as retaining beads and lugs, which maintain the closure in a closed position when it is not properly aligned to be opened. Such closures often have either one or a limited number of positions in which the parts must be aligned in order to be opened. The opening position for such closures is often referred to as the firing position, and in some cases, closures must be in the firing position in order to be closed, as well as to be opened. Since most such child-resistant closures either require or allow the closure to be closed while aligned in the firing position, after such closures are closed by the user, they may remain aligned to be opened, thereby defeating the intended purpose of the child-resistant features therein. Therefore, it is desirable to provide a child-resistant closure which maybe closed regardless of its alignment and is automatically displaced out of the firing position when the user closes it, thereby reactivating the child-resistant features thereof.
It is an object of the present invention to provide a closure with a child-resistant opening mechanism.
It is another object of the present invention to provide a closure having a child-resistant feature that automatically displaces the closure from the opening or firing position when closed by a user.
The apparatus of the present invention relates to a flip top closure having a child-resistant mechanism which may be utilized in conjunction with a container finish such as a neck, fitment or other finish which is incorporated as part of or attached to a container. The flip top closure of the present invention provides a child-resistant opening mechanism that prevents opening when not properly aligned and also displaces the closure from the firing position as it is closed. This closure may be used with a variety of containers, such as tubes and bottles.
More particularly, the apparatus of the present invention a flip top closure including a cap with a top wall and a downwardly depending sidewall which is attached to an outer ring via a small hinge line which extends along a short length of the periphery of the ring and the depending sidewall. The outer ring engages a rib, or similar structure, located either on the base portion of the closure or the container finish, thereby allowing the ring to rotate about the container finish. The hinge allows the top to rotate about the hinge to 90xc2x0 and beyond. The base portion of the flip top closure maybe threadably attached to the neck finish, or fitment, snap fitted thereon or formed integrally therewith.
The hinge allows opening of the container by allowing the flip top to rotate about the hinge line. The flip top may be opened by upward pressure applied to a thumb tab located thereon.
The child-resistant mechanism of the present invention includes a rotational follower and opening follower which may be aligned on a retention tab mounted along an inner edge of the downwardly depending sidewall of the flip top or cap and at a 180xc2x0 angle in relation to the location of the hinge. The mechanism also includes a rotational cam and opening cam which may be formed within a retention lug located on the container finish adjacent a retention bead. The opening cam and opening follower interact to allow the cap to be opened when the closure is in the firing position.
The rotational cam and rotational follower may interact to displace the closure out of the firing position as it is being closed. The rotational cam serves as a means for biasing the rotational follower, thereby biasing the entire cap. The firing or opening position refers to the rotational alignment of the flip top relative to the container finish, such that the opening cam is in a position to engage the opening follower when an opening force is applied to the cap. If the closure is aligned in the firing position, with the retention tab aligned with the retention lug, then the retention lug biases the retention tab either to the left or to the right of the lug, due to the engagement of the rotational cam and rotational follower, as the top is being closed. As downward force is exerted on the top as it is being closed, the engagement of the retention tab with the retention lug forces the flip top and outer ring to rotate so that the retention tab is positioned either to the left or to the right of the retention lug. The retention tab then snaps under and is retained by a retention bead located on the neck or container finish. The retention bead projects outwardly from the neck finish or fitment and may extend around the circumference of the neck finish or fitment being interrupted only by the retention lug. When the flip top closure is closed, the retention bead, in combination with the retention tab, prevents opening of the top when the retention tab and the retention lug are not aligned in the firing position.
In order to open the flip top, it must be rotated so that the retention tab and the retention lug are aligned with each other in the firing position. This alignment may be indicated by two arrows, an outer ring or first arrow, located on the outer ring, which is aligned with the retention tab and a neck finish or second arrow, located on the neck finish or fitment, which is aligned with the retention bead. The flip top is rotatable about a vertical longitudinal axis. The outer ring arrow rotates with the top and the retention tab so as to indicate the position of the retention tab. Once the retention tab and the retention lug are aligned in the firing position, a sufficient upward force applied to the flip top will result in opening. As force is applied to an optional thumb tab located on the cap, the retention tab will slide up over the retention lug, thereby allowing the closure to be opened.
Depending from the top wall of the flip top is a seal or gasket of a diameter sufficient to compress against an interior sidewall of the neck finish so as to provide a seal between the flip top and the neck finish or the fitment. This seal will prevent leakage of the package contents. An annular bead formed in the downwardly depending sidewall of the top wall maybe employed to help secure the gasket in place.